This invention relates to an alarm system which may be activated by a switch located within a dwelling to provide on the outside of the dwelling both audio and visual indications of an emergency condition.
Emergency indicating devices using externally mounted lamps and audio alarm devices, particularly for dwellings, are shown in U.S. Pat. Nos. 3,599,201; 3,624,635; 3,863,236; 3,911,425; and 4,003,040.
In some of these prior art devices, the existing externally mounted lamp housing is employed to house the audible alarm device and usually a second, emergency indicating lamp. Some of the devices shown in the above patents require that the circuit between the interior of the dwelling and the externally mounted lamp housing include at least three wires to accommodate the alarm feature requiring a modification of the existing wiring, and other patents require that a special lamp housing be installed on the exterior of the dwelling.
In all of these devices, the occupant will actuate a switch which causes an indication of an emergency condition be on the outside of the dwelling by the flashing of a lamp and/or the sounding of an audible alarm.
Such devices are useful to alert passersby that an emergency condition exists within the dwelling. These devices are also useful to assist a policeman, fireman or ambulance driver in locating the home or apartment requesting emergency assistance.